Marine vessel



June 9, 1925.

B. F. WRIGHT MARINE VESSEL Filed Marh s, 1924 2 Sheets-Sheet l Syvum/Hoz June 99 1925.

B. F. WRIGHT MARINE VESSEL Filed MELICh I5, 1924 2 Sheets-Sheet 2 In/vento@ @Ittoznaq S v an rer-all Application:meenemen 3,'

To NZZ'- wms'ft 112mg/ concer/Li.'

le it known that l, BE'NJ anni F. lrllniorrry a citizen ot' theUnited,States ot inerica,

and a resident ot Elk Hill7 county ol3A Gooch land, and State ol Virginia/have inven retain new and useful improvements in TaMarine Vessels, otl which the followinglis aV `l andolear speoiiieation;

invention' rela-tes to theepropulsion A olf l classesA of Vessels', driveneither zby steam7 eninesor any otherfapplied ypower whichl may be used for driving-anyclass o'tv'sorew or spiral propellers. and' it has tor'its objects to secure an yincrease of speed `and econz/nrf; ot operation. rThere-are'other advantages which necessarily follow,

et my proposed improvements.

l accomplish this in the'following` manner.y as shown by. the accompanying drawings, in whichi Fig. l is a side eleyation otvessel, the bon7| portion ot4 Whioh'is shown in settion;

Eig; Q' the line 2 2 of Fig. l;

Fig. 3 isy a View similarrft Figa@ taken on thelino'33ot1l*`igl;

th lneiel---et ot Figui;

e l Fi s. 5 and (3 are detail cross-sections 'showi modified orrns of'hullshaving double propulsion` means;

i lg'. 7 is' a detail View showing afur'ther" modified forni; and Fig'. 8 .is a View' showing' diagraniniatioallyiy one of the* old` terras of vessel propulsion.K

A. tube-like casing,

carrying. one: or more 'propellers provided at the bow oit' the Vessel;t Suitable bearings 5 and (Stor 'shalt 'l are `prcwidedin an upper :fore-castle rooin'J,`and at its lower end the shaft is "supported on' af'bearing. This lower bearing' 7 is'supported by opposite sides ot casingl by arms Whose' 'sides stand parallel Witlrtlie propeller'shazft, with its edffes only Confronting the current ot water passing through vthe easing."

yThe v'opeller blades should have avai-j."-V

ino' n h on their facesl inereasingfroni their trout or cuttinetede'es bach-to their ooc: u L

i u a electrical nieohanism internalcombustiony but. greater' speed and the avoidance or" lost l power are theinnnediat'e and special objects the hull of aA is a erossLsec-tional View taken onn in; 4 is a View 'similar to i' ig; Qgtaken on" in side elevation of a `hull extending the@ full" Width oli the vessel and enclosing` a shaltv et,"

Qiand Las? l Jai-rinrniiirzrniirwnrorrr, arianna, Vinornm."

VESSEL.

i924. smarrito. seeg'f positie-'edges Whe-re the Water finally leaves thenr, so-that Water may be taken easily andY `Without shock rand iinpinge as Vequally'E as possible on all` parts` ot' the bla-des. This would hel) to yore'ent afwhirlinomotion' ofl l t: A

more

therwater,l thereby nia-lling propellers ertoe-tive.

lllhile no claim yis Iliade' topany, special s torni or style` or propellers, therefare certain feature-s which inaybe Vused-fwhioh are necessary to obtain the best-results.: '.fhe

'faces ot all bladesshould*incline--slightly forward so as to throwwater*towards` the?A shaft by trav-Jing; it`v away from? the Wallsl ot -tlie'c-asing and the -bottoinot the bowot' the vessel,y as indicated byarrow lines` in-t l; also in diagranrlig; 7 in-whichhag Continuous Soren7l or spiral ASiis represented lnthese-gurespihe space-between the lines ot the arrows representsthe-Course ot theVv water current oreated bythe propeller7 the water beingy drawn nr'fron-the Walls of the fasingand 'the bow-ot thevessel. Thenr,

cliningfyt'orward of the propeller blades; it--is f thought, might be ot Sonie advantage in this special device, but sity because -properl ers r`of* ordinary 'alsoaca is noty an4 absolute necesi 'torni Will' l It `a; continuous screw isused, asl shown in"Fi,q.- 7, its piteh'ratio should preferably steadily increase from" its upper: Vto its lower` end;l and its' screw should-'be atleast a doubleV screw rather-than single-throadA screw; thatl is', two or more `such-'yanes should Wind aroundand -be Ysecured* to" the shat'tand their pitch ratio ContinuepappropriatelyY to increase vto their fend.-= lhat they properratio of pitchjinerease Woufld'be will' always depend on'a variety loi circumstances andmust be left largely to the judgment and experience ot the yess'els design-ier;l this'has` It will fi (l or at least near that angle, will be found best for best results. At this angle, it appears best for throwing a swell of current back under the vessel so as to fill in its wake and give a lifting effect to the stern, and at the saine time the propellers will have a decided tendency to .lift the vessel in front from the direct action of the engines, thus not only meeting swells, but also causing the vessel to ride higher in the water, thereby avoiding a proportion of the resistance in front; also this angle gives two-thirds of the engine-driving-power for a forward pull, its other third being devoted to an upward pull; and, thirdly, it makes the ship glide more smoothly7 and prevents plunging so deep into the ocean swells. Lastly, this angle gives suhcient force from the engines to hold the vessel steady or from careening; yet such force is in no way taken from the actual forward and upward pulling power; that is, if 1500 H. l). were applied, 500 H. P. would be given to holding the vessel steady in an upright position, yet this same force would not be taken from the lifting power of the engine any more than the pulling on a rope and thus keeping it taut detracts from the power applied to an object at its other end. V@n the contrary, it adds to the ease of propulsion by holding the vessel more steady from rolling.

Suitable power is applied to shaft 4: in room J, somewhere between bearings 5 and G, as indicated by 72. No form of any special connections with the driving power' can properly be given here, because such connection must depend on the kind of engine used ;v also it may in some cases depend on the construction of the ships hull. It may bel connected with the driving power by a crank, toothed gearing, worm gearing, or otherwise-the various ways in which this may be done forms no part of my invention.

So far, but one system of propeller-s, secured on a single shaft, has been referred to. I will now describe my invention as it relates to a double system of propellcrs, as shown in Figs. 5 and G; that is, where two or more shafts are used, each carrying one or more propellers. The manner in which this is effected is identical with that of a single shaft, being but a duplicatie of saine and therefore needing no further description. The only change is in the casing enclosing the different systems.

Referring to Fig. 5, right-hand and lefthand Propellers are shown, which are adapted to rotate toward each other, as indicated by the arrows.n There parallel screws are used, the diameter of the screws, of course, would not be the saine as though only one was used, neither would their pitch and number of revolutions be the same; their pitch would either be of' a higher ratio, or their revolutions greater to secure the san e speed for the vessel. The object sought in such case is to construct a large vessel and yet one not carrying eXtra large propellers. A second object is that, by using parallel propellers, the vessel can be given a quicker and shorter turn, as these propellers may be driven by engines independent of each other and either one. may be reversed, giving a backward effect, while the vone on the opposite shaft pulls forward. A further object for using parallel propellers is to enable a vessel to be constructed with an unusually shallow draught and broad beam. rlhe object sought in this instance is not to reduce the size of the propellers, but to secure the shallow draught, shown in Figs. 5 and 6.

Casing l practically forms the bow, or a percentage of the bow of the vessel as adapted to my invention. lt must be distinctly noted that the depth of casing as shown through the line of section 4 4@ may be made to extend to the surface of the water above, so as to include the vessels full area through mid-section 2 2. On t-he contrary, it might not be necessary to include but a portion of said section 2 2 on account of the lift (rise) of the vessel as it moves onward through the water. For example, a steamship of forty-foot beam and draught need iot necessarily carry a casing over sixteenfoot depth by forty-foot beam and containing parallel systems of propeller-s, as indicated in cross-sections, .F 5 and 6. This feature (lift or rise of vessel), cannot be too attentively considered because it is to and on this angular up-pull of propellers that other very vital features depend.

Projection of the horizontal portion of the casing immediately fronting the uppermost propeller need not extend farther forward than a distance equal to the depth of easing through 4 4. lt could extend farther, or not so far, without detriment. An inclined portion of the casing is seen to begin at lO, or near where the angular portion meets the horizontal section of casing, eX- tend downwardly and backwardly, and terminate at the forward edge of the opening 12. The purpose of this inclined portion is that the current may be deflected downwardly so as to throw the force of the swell, that is, its crest, at a given point under the vessel.

The part of the casing immediately enclosing the propellers extends substantially at the same angle as the` propeller shaft, or it may be so shaped as to best suit one or more systems of propellers. The casing is formed preferably of ship-plates, built into and onto the .hull of the vessel, which in effect strengthens the front of the vessel and is less difficult to build than long tapering bows, because it conforms nearer to true mechanical shapes. lts construction is therellO lli

fore leftto the ship builder. The beginning of the casing commences at' 13 by projecting the plates at a point approximately midship of the vessel.

By reference to Fig. l and considering a given shaped tubular casing lying at an angle of 30 degrees, it will be seen that przmtically no part, or very little, of the bow is left for resistance. It should also be noted that the angle of the propeller shaft need not be identical with that of the casing, it may be slightly more or less elevated. For example, it might be 3l degrees, while the mean angle of the casing remains at 2l) degrees. rl`his would tend more directly to throw water from the uppermost inside, of the casing, which would be the side of resistance, were the water not drawn from it. But in point of fact, l consider an angle of 30 degrees best for better results and that the angle of shaft and casing should be the same.

Referring to diagram, Fig. T, it will be observed that line fm, drawn diagonally at 30 degrees across the casing, is exactly twice as long as the line n., drawn at a right-angle to the casing; consequently, any reduction in the diameter orV size of current removes the water from the bow of the ship a distance twice that of the reduction of the radius. Attention must be called to the fact that, as the ships line of travel must always be at an angle to the line of current from the propellers, it is evident that any reduction of current makes resistance in front of its line of travel impossible; propellers being the moving force, the ship would have to perform the anomaly of doubling its speed on them and of running ahead of its drivingl power before it could run into any resistance. from the water in front. Any slight contraction of the diameter of the current, for this reason, makes it easier to avoid resistance.

My invention being a principle, or combination of principles, intended to avoid resistance at front as one of its main features, Fig. T is given only for purposes of illustration. As the mechanism and machinery is extremely simple in this device aud its principles are practically everything, it is necessary to explain these at some length. The continuous spiral screw, shown in Fig. T, Awould in almost every instance be preferably of two or niorc Yanes, their pitch ratio increasing from upper to lower end, because in every form of propeller used their Yanes should impinge steadily on the current as it passes. Their diameters, or length of blades, may be decreased, as pitch increases, 'to advantage, because the current here is smaller than above, having been contracted by the action of the propellers above. llhere a propeller of continuous spiral vanes is used, it is suggested that they be secured to the shaft without a hub; they may be conveniently formed of'sheet-metal plates secured to the shaft.

l-illpropellers other than continuous spiral screws may be so made as to be adjustable to dinlerent positions on the shaft. This is desirable so that experience may be gained for best results, practically without cost. They should, however, be so located aste impinge on and assist in keeping the dialneter of the current contracted, or in further contracting it, until it leaves the lowest propeller. The propellers acting to draw the water from the sides of a casing into the current, tends to create a film of dead water outside of the current, and at high speed of the propeller-s is likely to create somewhat of a void or a partial vacuum. fr high degree of void is not desirable because the outside water would rush in with tremendous force and thus create a resistance, something this invention is trying to avoid. rlhe higher the speed of the propeller, the greater the suction from the walls of the casing. To' control the degree of void, adjacent the walls, a. counter-lmlancer air-valve l5 is provided, preferably in the upper wall of the casing, said valve being connected to a pivoted scale-beam on which is mounted a slidable weight to regulate the opening and closing of the valve, depending on the amount of suction created by the propellers.

ln Fig. 2 is shown'the preferred form of the bottom of the vessel from the dischargeend of the casing l to the eXtreme end of the stern when a double series of propellers is used, the object of this particular shape being to more cii'ectually utilize the uplifting force of current from the propellers.

Theory of ope/ration.

Figuratively, it may beV said the purposes and objects of my invention are attained by taking a propeller or propellers from the stern of avessel and placing same in a tubular casing of certain preferred angle at the bow of 'the vessel, as indicated in Fig. l. The greatest objects of this are to avoid resistance of the water in front, and to prevent the loss of power, as happens when the propellers are located at the stern.

Resistance of water to all moving bodies, including ships, power or sail, is a natural law and will always resist all bodies coming in direct contact with it at a rate which incre-ases in proportion as the square of its rate of speed increases. To double the speed with a given resistance requires that the power must be increased four times, and so on up, still more prodigious at each successive attempt for increased speed. I avoid this resistance at the front, or bow, as fol- 'l lows:

Power being applied which sets the pro- 'to ride higher out of the water.

pellers in motion, they in turn set in motion a current as indicated by the arrows. As a section of tubular casing extends forward and parallel with th-e surface of the water, the current created coines only in contact with the bevelled front edge 16 of the easing. An atmospheric pressure of fifteen pounds per square inch, to which must be added the weight of the water above, causes the water to enter the tubular casing in a current to the propellers when same are in rapid niotion, precisely on the same principle and in the same manner that water flows through any tube or pipe towards a vacuum. The degree of contraction ofthe current will, of course, depend on the speed and pitch of the propellers. lf the speed of the propellers were increased to such speed as to equal the effect of a perfect vacuum, the current flowing` to them could no long-er be further contracted because at. such speed, full atmospheric and water pressure would be attained. But contraction under such conditions wonl-d be very great, far more than necessary to avoid frontal resistance because it is, in fact, the ships speed toward the water `and not the speed of the water to the ship which could cause resistance in this particular case. The speed of the vessel being always dependent on the pitch and revolutions of the propellers, the vessel could in no instance run into resistance.

It is evident that as the propellers first act on the water, diverting its course, contractingthe size of the current entering the casing, and by impinging on same exerts aforce for pulling the vessel forward, it can in no wise resist same at bow. It is not too much to say that resistance under this arrangement is impossible at a ratio even approximating the ratio of the square of the rate of speed, because clearance and contraction of the current everbecomes greater as speed increases. I do not affirm, however,that absolutely all resistance is avoided, but only that it is so .relieved that it cannot resist at a ratio proportioned to the square of the rate of speed.

Another feature necessarily flowing' from this is a contracted current projected at an angle into dead water beneath the vessel, where it will expand again in a swell in the ressels wake. There appears to be certain advantages in this.v one of whichis a .negative one, in that it does not throw a whirling` torrent from the stern as is the case in present practice. The magnitude. and intensity of this swell I am not able to estimate, still less to describe or to represent by art, but that it is tremendous, even 4with small ressels, cannot be doubted. It is seen in the wake of all self-propelled vessels.

A vstill further feature is an upward lifting force by which the vessel may be made This, of

course, means yless resistance per cargo. If I ain told thatall propellers may be Vset at a lifting angle at stern,l answer that all such lifts tilt the vessel forward to sink it deeper toward the bow. This swell referred to under the vessel actsV in conjunction with propeller-s in their lift of the vessel.

Referring to Fig. 8, the very opposite takes place. lf seen as it really is, instead of as indicated by arrows, we would see a current beneaththe vessel, Lkbeginninge," yat its greatest mid-section, increasing` in Vvolume and intensity as it nears the stern, and "becoming a rolling, twisting torrent `beyond the propeller. But only apercentage of this is seen because it takes place beneath the surface. lV-e may often see water lowered at the stern, where it were best it ,wereA highest, due to the action ofthe propeller beneath. This propeller is busy withdrawing atmospheric and `water pressurel from the` vessels stern, pressure which ought to be the vcsscls greatest driving power. Here again, as may be seen as indicated by arrows in Fig. S, the sides of the propeller Vblades next the vessel are running away from the water, a fact detrimental: to propulsion in this instance because it draws pressure away from the stern `of the boat.

n properly shaped vessel may and should have considerable lift. But lift must always depend on speed; the greater the speed, the higher the boat rides towards the Asurface. This is especially true of sail ships because they have no propeller at the stern luider-mining and drawing water from their bottoms; increased .ratio of resistance at the bow is their only difficulty. To illustrate by ligures, we will suppose cach vessel indicated by Figs. l and 8 `to be lll-foot draught and contain 300 square feet across their greatest v,immersed section. Each would then have over 950,000 lpounds of atmospheric and water pressure on each of the opposite sides of this section; that is, at their bows and sterns .the pressure at the bow and at the stern pressing in opposite directions in such exact poise that it may be said a child could move them so far as resistance of friction is concerned. lf we next suppose each vessel with no driving power, but with kno resistance in front and still having its atmospheric and water ,pressure at stern, cach would glide forward at an incredible speed, assuming' them to .inaintain their levels and with their .sloping` bottoms forming inclined planes down which they glide. Now suppose the resistance to be removed at the bow by a 500 H` l). engine driving propellers lin the casing, as in Fig. l: then the principles I propose to use in steamship propulsion will .be clearly seen. Vith the resistance removed by this engine, which is also exerting a pulling and a lifting force, the water and atmospheric preskce y lent of perpetual motion, or a sure behind over 000,000 pounds in the size ship mentiol'ied, if sunk to its natural level), and the lifted weight of the vessel will force the vessel down a continuous incline toward the space constantly being cleared at the bow, these being, in a nut-shell, the principles on which I base my invention, the great object sought by means of this device being to so relieve self-propelled ships from all resistance except friction that they may travel free in response to the application of power on the principle of a -fly-wheel.

Any body, once in full motion, requires no further force to maintain its acquired motion than that necessary to overcome friction and any air or other resistance it may encounter. This is equally true of a batt-leship and of a train, but the friction on the train is a great many times greater than on the battleship. Extra power necessary to be expended up-grade is compensated for, theoretically, down-grade.

But my illustration above of the 500 II. I). and how its force is expended is apt to be construed to mean that I claim for my device (or principles of propulsion) not only this whole 500 H. P., which is the full force of the supposed engine, but also an extra force of over 950,000 pounds pressure at the stern, plus the lifted weight of the vessel down the incline of the keel. This would be claiming something for nothing, the equivalittle better, and would, of course, be absurd. On the contrary, I claim for my ship not one iota more power than is expended by its engines, but what I do claim is that by this arrangement the resistance of the water Vis relieved from the bow of the ship by the contracting force of the propellers; that the ship is lifted in the water by the lifting force of the propellers, thus further reducing frontal resistance; that the power exerted by the engine in removing resistance at the bow is compensated for by the pressure of the water and air at the stern; and that the `en gine power exerted in raising the ship is compensated for by the pressure of the lifted weight Clown the incline of the keel; and that all the power of the engines that is not devoted either' 'io removing resistance 'in' front or to lifting the vessel higher inthe water is used as a direct forward pulling force.

The end of the casing in front of the pro-4 pellers has already been mentioned, but more should be said of itsvobjects in connection with the propellers in keeping back an excess of water, that is, a body in excess of that in the actual path of the ship. At the same time, it largely prevents that whirling motion common to all propellers at the stern, and, by preventing this whirling motion, the propellers impinge more forcibly on the water. Thin steel ribs lll may also in some instances be placed to advantage and without obstruction tothe current.

I now ask that attention be turned to Figs. l and 8, and that they be considered with reference to each other. to say that the water is not resisting in the path of Fig. l, as itis in that ofFig. 8; that a whirling torrent is no longer being thrownfrom the stern of Fig. 1 as it is from Fig. 8; that no matter what minor resistance there may still be with the Fig. l construction, that resistance cannot increasev at a ratio proportionate to the square of the rate of speed ofthe ship, as it would do with the Fig. 8 type, to attain all of which I claim not a single principle or law of nature has been opended. I also thinlr my claimwellfounded that a system of several propellers mounted on a single shaft within a casing excluding all water except that to be removed, as and for purposes described, is more effective as a pulling force than one at the stern'can be as a driving one, equal power being applied to both.

I-Ieretofore I have referred to my invention as it rela-tes to avoiding resistance at the bow, this to prevent confusion.V The principles on which this resistance 'increases according to the square of the rate of speed is well understood. It is'not so well'understood that a still greater expenditure of power is unnecessarily yrequired at the stern because of the great loss occurring there, and that because of this loss the power necessary to propel a ship must be multiplied by the cube of its rate of speed, insteadl of by the square7 necessitated by the resistance in front. As this is a mechanical loss, not running according to philosophical principles, practical considerations so that in afew instances it has been found to be a little less, but generally the cubel is correct, which is to Say that in increasing speed from a rate of ten miles to thirty miles an hour, power must be increased twenty-seven times, because the rate of increase of speed is three times, and the cube of three is twentyseven. Callingattention, then, to the fact that three times three is vnine and nine times three is twenty-seven, brings me to the last and most important feature of my invention, which consists in leaving ofi' propellers at the stern and enclosing them in a suitable casing at the front, as herein described and illustrated. Observing that lost force at the stern greatly exceeds resistance at the bow in all high speeds in the present prac'- tice, I consider the objects sought and the principles employed to attain them in my invention have been sufficiently explained.

In the example just cited, it was shown how a loss of power at the stern, as seen in Fig. 8, could exceed resistance in front in proportion of two to one.l yHad the rate I think it fair the amount of it varies according to vtimes is 64,0004 H. P..

been carried higher, say 'from l0 miles Yan hour towel() miles, the proportion `wouldhave been as threev to one, and so on up with each increase of speed. It is the avoidance otloss at the stern and resistance in trent which Ielaim to attain by my invention, as shown in Fig. l of the accompanying drawings. Toexplain clearly the division of unnecessary power between this resistancein front anc; this loss at the stern present methods of propulsion requires one further illustration. t Say a ship traveling at a rate of ten miles an hour with an expenditure ot' 1000 H. P., and it is desiredy to increase its speed 'from ten to 40 miles, or four tiines. First, its 4power must be multiplied by the square its rate ot speed to:

take careotthe increased resistance, `i. e tour ,timesl tour times 1000 H. l., or 16,000 H. P., which would rbe the actual resistanee of the water in front. But, as actual mul-Y tiplication of power must be by the cube ot the rateot increased sped, wemust niultiply again, and we say 10,000 H. P. four Subtracting 16,000 H.l P. (the power required by increased frontal resistance) troni %',000 H. P. leaves 48,000 l. P., Vwhieh must be' credited to the loss by the propeller the stern, because we have already allowedV full legal resistance ot 16,000 H. P.; therefore, any. manner by which the propeller is lett ott or removed from` the stern, withoutany corresponding disadvantage, would in the above ease save this encessiae lossl et power. ll this has beenf said to emphasize the important vttature ot getting propellers away trom the stern, an'diit should be observed that the methods herein employed are those olf principles rather than ot nieehanism. f

I N ow l Claim that a system ot' propellers as illustrated in Fig. l will tar exceed in etteetivepropelling power any which may be placed at the stern, eqiial power applied in both eases. It follows inevitably ,that this great lossot power at the stern, whieli add'- ed to resistance in front mounts rip to a multiplication of power the cube et' the rate of increase ot speed, woiild be saved by pla'oing lpropellers as indicated Fig. l..

lMy main objects therefore, are' to avoid these great dittioulties to ship' propulsion in such a nianuer as to leave only iiictioir to be overcome, and I aver that trietionf'is bfut negligible compared totl're one great rdithculty of frontal resistance. Great ocean Steamers carrying three and tour huge steeli masts .with great spread ol sail, stand out as witness-es to the errors in our presentE metre odset propulsion to Lwhich l have called attention: t They testify that added speedI by further urnul'ation of power applied to propellers at thesternhasreached the utmost limit.; eonsstent ,with reason and economy. Applied power being superior to sails, why

use sails at all? Why not more pow/er?.v Because the" additional power gained by the use oi' sails is all ntiliZed in overcomingv resista-noe in front, while that .applied to the 'propellers would be mainly kicked away at the stern. t

Among minor 'advantages incidental to the principles as applied to the above pro posed new method of boat propulsion, should be mentioned the eXtra litt eaused by increase ot speedincreased speed meaning higher litt andhigherlift meaning increased speed. Among various other advantages, one other is especially worthy of mention. l allude to' that feature whereby the vessel is held more iiijnily from rolling by the anguiar uppiillot the propellers in front.

YVhat I claim is: l. In a marine vessel, a hull having a bow frontwall inclinin'g downwardly and rearwardly andI merg-mg gradually with the bottom of the hull, a easing, on the front wall ot the hull :forming a chamber having the width Oft' the vessel, said chamber being open at its front end and at its lower rear end, andy an inclined propelling 4means located within saidfchai'nb'er a'nd adapted to drive the water therein downwardly and' rearwardly, as and for the purposes set forth.

2.V In a, marine vessel, ahult having a bow front-,wall inelinin'g downwardly and rearwardly tothe bottom ot'q the hull at a point approximately mi'dshipf` thereof,l a casing er:- tendled fromV said bow trent-wall toward the `front endf of the vessel, said casing' throughout its ylength being approxiniately equal in width to the beamot they vessel and having an open rear end and also a front end wholly open, wl'i'ere'by only its 'front edge offers a resistanee against the water when the vessel. is moving forwardly, and a propeller means located within said easing and inclined downwardly and rearwardly substantially parallel with saidbow front-wall.

3. In a marine vessel), a hull having a bow front-wall inclin'ing downwardly and rearwardly to the bottom ot the hull at a point approxii'nately l i'nids'hifp thereof, casing having a bevelled trent ed'geefrtended trom said bow front-wall' tothe trent end ot the vessel, said casing throughout its length being approriinatelyv equalv in width to the .beam oil the vessel and havin?T an o ien rear end and also a front end wholly open,

whereby only lits front edge oliers a resistance against the water wh'en the vessel is moving forwardly, and a` propeller -means located within said casing and kinclined downwardly and rearwardly substantially parallel with said lbow front-wall.

t. iIn a marine vesseha hu'll having' a bow front-,wall inelining downwardly and rearwardly to the bot-toni of lthe hull at a' point approximately inidship thereof, a 'easing extended trem said bw trent-wall toward the front end of the vessel, said casing throughout its length being approximately equal in width to the beam of the vesseland formed with a downwardly and rearwardly inclined wall portion at its lower end which is substantially parallel with the bow front-wall and having an open rear end and also a front end wholly open, whereby only its front edge offers a resistance against the water when the vessel is moving forwardly, and a propelling means located within said easing and inclined downwardly and rearwardly substantially parallel with said bow frontwall.

5. ln a marine vessel, a hull having a bow front-wall inclining downwardly and rearwardly to the bottom of they hull at a` point approximately midship thereof, a vcasing extended from said bow front-wall toward the front end of the vessel, said casing throughout its length being approximately equal in width to the beam of the vessel and having an open rear end and also a front end wholly open, whereby only its front edge offers a resistance against the water when the vessel is moving forwardly, and a propelling means located within said casing and inclined downwardly and rearwardly substantially parallel with said bow front-wall, said propelling means embodying a plurality of propellers in alinement with each other and of less diameter than the inside of the casing to provide a substantial clearance space between the peripheries of the propellers and the walls of the casing.

(l. In a marine vessel, a hull having a bow front-wall inclining downwardly. and rearwardly to the bottom of the hull at a pointapproximately midship thereof, a casing extended from said bow front-wall toward the front end of the vessel, said casing throughout its length being approximately equal in width to the beam of the vessel and having an open rear end and also a front end wholly open, whereby only its front edge offers a resistance against the water when the vessel is moving forwardly, and a propeller' means located within said casing and inclined downwardly and rearwardly substantially parallel with said bow front-wall, said propelling means embodying a plurality of propellers of decreasing diameter toward the lower end of the propeller-shaft and in alinement with each other and of less diameter than the inside of the easing to provide a substantial clearance space between-the peripheries of the propellers and the walls of the casing.

7. ln a marine vessel, a hull having a bow front-wall inclining downwardly and rearwardly to the bottoni of the hull at a point approximately midship thereof, a forecastle room located in a plane above said bow front-wall and in front of the same,1a casing extended from the bow front-wall toward the front end of the vessel, said casing throughout its length being approximately equal in width to said forecastle room and having an open rear end and also a front end wholly open, and a propelling means arranged in parallel relation to the bow frontwall and embodying a shaft extended into the said forecastle room, a thrust bearing for the upper end of said shaft secured against the front-wall of the foreeastle room, and a plurality of propellers mountedon said shaft inside of said casing.

8. In a marine vessel, a` hull having a bow front-wall inclining downwardly and rearwardly, a forecastle room in a plane above said front-wall and extended beyond the same, a casing in front of said front-wall and forming a chamber underlying the foreeastle room, a propelling means located in said casing and lying approximately parallel to the front-wall, said casing being equal in width to the beam of the vessel and being wholly open at both ends, and also provided with longitudinal ribs on its interior face of its walls to prevent the whirl of the water tiowing through the same.

9. n a marine vessel, a hull having a bow front-wall inclining downwardly vand rearwardly, a forecastle room in a plane above said front-wall and extended beyond the same, a easing in front of said front-wall and forming a chamber underlying the forecastle room, a propelling means located in said casing and lying approximately parallel to the front-wall, said easing being equal in width to the beam of the vessel and being wholly open at both ends, said frontwall being curved at its lower end to merge gradually with the bottom-wall of the hull, and said bottom-wall being formed with a longitudinal groove to effectively utilize the uplifting force of the current formed by the propellers.

In testimony wl'iereof l hereunto atlix my signature` BENJAMlN FRANKLIN lVRIGHl. 

